There is a delicate balance between pathways which promote oxidative stress and inflammation, through stressors such as angiotensin II and hypercholesterolemia, and pathways which are protective by promoting an antioxidant and antiinflammatory state. The balance/imbalance between these pathways influences susceptibility to atherosclerosis, hypertension, calcific aortic valvular stenosis, and thrombosis. The overall theme of this Program is to define endogenous mechanisms that protect against, and predispose to, cardio- vascular dysfunction and disease. The Projects in this Program will focus on several novel hypotheses. First, findings during the current funding period indicate that PPAR? dependent pathways in both endothelium and vascular smooth muscle protect against development of atherosclerosis. Studies are proposed to examine mechanisms of protection by PPAR? and to test the hypothesis that PPAR? protects against thrombosis and calcific aortic valvular stenosis. These studies are timely and clinically relevant considering the controversy about effects of thiazoledinedione drugs, which activate PPAR?. Second, the renin-angiotensin system is a key mechanism in pathophysiology of hypertension and stroke. Studies are proposed to test the hypothesis that the renin- angiotensin system contributes to cerebral vascular dysfunction, calcific aortic valvular stenosis, and thrombosis. Third, mechanisms will be studied by which PPAR? modulates rho kinase turnover and activity, and thus may contribute to altered vascular structure and vasomotor tone in hypertension. Fourth, studies are planned to test the hypothesis that a specific oxidation reaction, protein methionine oxidation, impairs anti-coagulant function of the endothelial protein thrombomodulin, and thereby contributes to the prothrombotic phenotype of atherosclerosis. The Program is tightly focused and cohesive. It consists of four projects and three cores. The investigators use sophisticated experimental approaches, including tissue-specific genetically altered mice, to clarify fundamental mechanisms. The investigators are productive, highly interactive, and the environment is outstanding. If major goals of the Program are accomplished, which is probable based on the track record and synergy of the investigators, the findings will clarify important mechanism related to cardiovascular dysfunction, and may allow translation into improved treatment of atherosclerosis and other cardiovascular diseases.